Sigmoidoscope and illuminating means therefor

ABSTRACT

1,081,849. Sigmoidoscopes. SMITH KLINE &amp; FRENCH LABORATORIES. March 22, 1966 [March 22, 1965], No. 12686/66. Addition to 1,048,600. Heading A5R. [Also in Divisions G2] The sigmoidoscope and lighting unit of the Parent Specification is modified in that the lamp unit 12a is formed with a sleeve 32a which fits completely around the end of the sigmoidoscope tube 14a when the sigmoidoscope and lighting unit are secured together. The tube 14a is also formed with slots 41a, 42a to mate with projections 40a on the eyepiece 13a, and with an aperture 49 to align with the air inlet or outlet nipple 18a on the lamp unit. A sealing ring 47 is provided either on each face of the lamp unit as shown, or on the end 19 of the tube 14a and on the eyepiece. The rod 23 carrying the lamp at its distal end is detachably secured by a pin and slot conneotion 52, 51 to a tubular member extending from the projection 25. The sigmoidoscope may be made from a high density polyethylene and the inside of the tube 14a may be given an abraded surface.

March 19, 1968 J. M. FIORE ETAL SIGMOIDOSCOPE AND ILLUMINATING MEANSTHEREFGR 2 Sheets-Sheet 1 Filed March 22, 1965 SIGMOIDOSCOPE ANDILLUMINATING MEANS THEREFOR 2 Sheets-Sheet 2 Filed March 22, 1965 0 M $0O R E TE NW mm m V T IF. mp i Mm l- M Q ww Q Y B \J 8 finite 5 Claims.(Cl. 128-6) ABSTRACT OF THE DISCLOSURE An illumination unit for use witha speculum device consisting of a housing means, releasably secured tothe proximable end of the speculum, elongated support means releasablysecured to the housing means, illuminable means secured to the free endof the support means, and disposable contamination means surroundingboth the support and illuminable means.

This application is a continuation in part of our copending applicationSer. No. 339,479, filed Jan. 22, 1964, now abandoned.

This invention relates to a single use disposable sigmoidoscope andillumination means therefor, and more particularly to a contaminationprotected non-disposable light source means positioned internally and atthe distal end of a disposable sigmoidoscope.

In the use of medical speculum devices generally a light source isdesirable to increase the accuracy of more precise types of diagnosticexaminations, and also to facilitate various treatment processes carriedon through the device. Ordinarily such a light source may be one whichis ordinarily separate from the instrument, or one which is attachedthereto, and arranged in either instance to have light directed into orthrough the speculum. These and other similar arrangements suffice forshort-length speculum devices where relatively low lighting power of thelight source is sufficient. However, in the longer speculum instrumentssuch as a sigmoidoscope, where the effective length may be on the orderof 25 centimeters or more, and where the instrument is of necessity anenclosing cylinder, more lighting power is necessary because of distanceinvolved and the area to be examined. Because of these notablerequirements, it is usual practice in sigmoidoscopes for the lightsource to be placed inside the instrument and at the distal end thereof.In this position, however, the light source is subject to contaminationfrom contact with the patient directly or indirectly so that withoutmeans for maintaining the light source in a sterile or sanitarycondition immediate reuse for other patients is prohibited. The highdesirable disposability of the sigmoidoscope is therefore limited bybeing combined and employed with a lighting means which is notdisposable.

Accordingly, it is an object of this invention to provide an improveddisposable speculum and illumination means.

It is another object of this invention to provide an improved disposablesigmoidoscope with self-contained internal illumination means externallyreleasably secured thereto.

It is a further object of this invention to provide means forcontinuously maintaining internal illumination means in a disposablesigmoidoscope in a sanitary or sterile condition.

It is another object of this invention to provide an externallyattached, internally positioned, illumination means in the form of anelectrical lamp adjacent the distal end of a disposable sigmoidoscopeand prevented from direct or indirect contact with the patient.

It is still another object of this invention to provide States Patentlighting means for disposable sigmoidoscope having the lighted portionenclosed in a sanitary casing and positioned internally of thesigmoidoscope at the distal end thereof.

Briefly described, this invention includes, in one preferred form, thecombination of a readily and economically disposable sigmoidoscope,together with an internal light source which is protected fromcontamination. A rechargeable battery unit is releasably securedexternally at the proximal end of the sigmoidoscope, and a support rodprojects into the sigmoidoscope terminating adjacent the distal endthereof. An electrical lamp is positioned at the end of the support rodto provide a light source closely adjacent the area to be examined. Aremovable transparent sleeve or cover about the support rod maintainsthe support rod and lamp assembly free from con- 'tamination during theuse of the sigmoidoscope.

In another embodiment, all of the materials of construction and physicalfeatures are the same, excepting the effective length of the lightsupport rod, which is substantially shortened to about 15 cm. to adaptthe instrument to examination of the middle portion of the sigmoidcolon, referred to in the medical art as a proctoscopic examination.

In a third embodiment, the effective length of the rod support of therectal speculum of this invention is reduced to about 8 cm., for what istermed an anoscopic examination. Thus, variation of the effective lengthof this instrument is within the scope of the invention to accomplishthe particular species of rectal examination intended by thepractitioner.

It is also contemplated as within the scope of this invention to matespeculums and support rod of dissimilar lengths. For example, a supportrod of about 7 cm. may be employed with a sigmoidoscope of about 25 cm.in effective length. This is to accommodate those medical practitionerswho prefer a proximal light source rather than a distal one whenconducting a sigmoidoscopic ex- "amination.

This invention will be better understood when taken in connection withthe following description and the drawings in which:

FIG. 1 is a cross-sectional assembly view of one preferred embodiment ofthis invention.

FIG. 2 is an exploded view of the assembly of FIG. 1 denoting theinterfitting relationship of the illustrated parts.

FIG. 3 is a cross-sectional assembly view of another preferredembodiment of the lamp unit of this invention; an

FIG. 4 is an exploded view of embodiment of FIG. 3.

Referring now to the drawing, wherein like parts have been designatedwith like reference numerals, and to FIG. 1, in particular, there isillustrated one preferred configuration of a sigmoidoscope assembly 10in accordance with the teachings of the invention. sigmoidoscopeassembly 10 comprises a three part arrangement including a sigmoidoscope11, a light unit 12 and an eye piece 13. sigmoidoscope 11 in onepreferred form of this invention is a single use disposablesigmoidoscope similar to the sigmoidoscope disclosed in copendingapplication Ser. No. 322,597, Fiore et al., filed Nov. 12, 1963, nowabandoned. In the mentioned copending application a similarsigmoidoscope is described which is manufactured or produced by amolding process from a readily and economically disposable materialincluding such materials as produced from fibers, therrno-plastics, etc.Accordingly, scope assembly 10 may be fabricated from plastics havingthe aforementioned features, such as economy of material, durability,sterilizability, and suificient rigidity without brittleness. We havefound that the thermoplastics known the major parts of the as the linearpolyolefins, which can be readily injection molded, give disposableinstrument components having the right combination of physicalproperties.

Thermoplastic resins, particularly the polyolefins, possess most of theproperties desired in the material for the speculum of this invention,because of their moldability, flexibility, lack of toxicity, and generalgood resistance to deterioration by environment conditions and aging.While we can use any-solid linear polyolefin successfully for thepractice of this invention, we prefer to use those linear polyolefins,and particularly linear polyethylene, having a density of 0.940 to0.980, which in the molded product contributes to a lack of sharp edges,a feature which is important to the present invention. Linearpolyolefins particularly suitable for injection and/ or extrusionmolding in accordance with this invention are the high densitypolyolefins made, for example, in accordance with the Hogan and Banks USPatent No. 2,825,712, issued Mar. 4, 1958. This family of polyolefinsare of higher density than the original high pressure polyolefins. Toillustrate, polyethylene of this type has a density of 0.960 to 0.980,as compared to higher pressure polyethylenes of about 0.920. Even whencopolymerized with minor amounts of other olefins, such as l-butene, thedensity of the copolymer is above 0.940. ALATHON 7050, a linearpolyethylene having dielectric properties, is a typically suitablelinear polyethylene for the practice of this invention. Theaforementioned application also describes a single use" device whereinthe sigmoidoscope is completely disposable, i.e. not intended for anyfurther use, after a single use. The disclosure and teachings of thementioned copending application is included by reference herein.

In the present invention, the disposable sigmoidoscope 11 includes, forexample, linear polyolefins, such as linear polyethylene orpolypropylene barrel or hollow cylinder portion 14 which is providedduring the forming or molding process with a pair of ridges or shoulders15 and 16. Ridges 15 and 16 are adapted to position and retaintherebetween a suitable hand guard 17. Hand guard 17, which may be ofthe same material as cylinder 14, is assembled on cylinder 14 in theposition illustrated by being forced over ridge 15. Because of thepliable nature of the linear polyolefin material of guard 17 andcylinder 14, the described force fitting is not detrimental to thedevice, and hand guard 17 is releasably retained in the illustratedposition. Cylinder 14 is also provided with a nipple outlet 18 betweenthe hand guard 17 and the proximal open end 19 to introduce or withdrawair from the interior of cylinder 14 during operative practice of thisinvention. Cylinder 14 is also fitted with a slidably removable bturatorassembly (not shown) which projects from open distal end 20 as is theusual practice in the art. The obturator assembly facilitates insertionof the cylinder 14 into a body orifice and is withdrawn prior to theinsertion of light assembly 12 into cylinder 14.

Light unit 12 as illustrated in its operative position in FIG. 1includes a housing 21 adapted to contain an electrical power source,such as a battery or rechargeable element 22. Battery element 22 in onepreferred form of this invention is a rechargeable nickel cadmium cellas is well known in the art. Attached to housing 21 is an elongatedrod-like support 23 which extends into cylinder 14 along and adjacentthe wall thereof terminating near the distal end 20. At the end of rod23 there is positioned a very small prefocused electrical lamp means 24as the light source for the sigmoidoscope 10. A suitable miniature lampis one rated at 2.5 volts, and 300 milliamperes, such as the GeneralElectric 1861D. Lamp means 24 is suitably electrically connected tobattery element 22 by one of several means, for example, by havingsuitable conductors extending through rod 23 or in a preferred form ofthis invention, by a single electrical conductor extending through andinsulated from rod 23, where a metal rod 23 is employed as an additionalelectrical conductor. Numerous other well known electrical connectionsmay be suitably employed without departing from the scope of thisinvention. Rod 23 may be of a telescopic or otherwise adjustable nature,or manufactured in various lengths, so that the distal position of lampmeans 23 in cylinder 14 may be varied, or so that light unit 12 may besuitably employed with various other similar devices having shorter orlonger similar cylinders such as cylinder 14.

In one embodiment of this invention rod unit 23 is releasably secured toprojection 25 of housing 21, with rod 23 fitting within an aperture 26in projection 25. The insertion of rod 23 into projection 25 also servesto provide the proper electrical connection from electrical conductingmeans in rod 23 to a suitable electrical conductor 27 leading to battery22. While the insertion of rod 23 into aperture 24 may be providedthrough various suitable known bayonet or prong means which close adefined electric circuit and effectively securely lock the elements inplace, it is contemplated that other electrical switching means such ason off switches may be employed which are operable by the practitioneras desired, and which do not involve assembling of parts.

The rod 23, together with lamp means 24 in the position as illustrated,is exposed during use to considerable contamination by the patient, andwould accordingly need to be sanitized or sterilized before eachsucceeding use. Otherwise transmission of various bacterial or virusinfections may take place from one patient to another or from thepatient to the medical practitioner or to associated coworkers. It isnecessary that the exposed rod 23 and lamp means 24 be maintained in asterile or sanitized condition such that it may be reused withoutnecessity of undesirable expensive and time consuming cleansingprocedures. Otherwise the numerous and highly desirable advantages whichflow from the use of a disposable sigmoidoscope are limited by a lightsource, when so employed, which is either not disposable in the samesense as the scope is disposable, or requires special cleansing whichwould delay immediate reuse for the same type of examination or withother instruments or devices as mentioned.

Accordingly an important feature of this invention is the use of adisposable closed end sleeve element 28 which is positioned to containrod 23 therein and to prevent any contamination of rod 23 or light unit12. Sleeve 28 may be produced from various materials and combinations ofmaterials, which may be rigid, semirigid, or flexibly soft. The onlycritical requirements of sleeve 28 is that the material be relativelyimpervious to fiuids for a reasonable time or otherwise preventtransmittal of virus or bacteria therethrough. It is also necessary thatthe closed end 29 be transparent or translucent to transmit light fromlamp 24 therethrough without substantial diminishing of intensity. Mostclear plastics meet these requirements and are suitable sleeve 28materials. By way of example, such materials may include pliofilm,polyethylene, cellophane, etc. In one preferred form of this inventionsleeve-s 28 are of a clear thin polyethylene film and from about A; toinch inside diameter.

The open end of cylindrical sleeve 28 is provided with an axial slit toform a pair of extending flaps 30 and 31. In the operative positionillustrated in FIG. 1, one of these flaps 30 from the underside of rod23 extends into the space between hand guard 17 and housing 21, and theother flap 31 extends over projection 25 and between housing 21 and eyepiece 13 externally of the instrument. These flaps serve a two-foldpurpose. They provide ready means for the practitioner to grasp toremove sleeve 28 from rod 23, and they provide further protection toprojection 25 and casing 21. One method employed to produce asatisfactory sleeve 28 includes providing a long narrow rectangularstrip of clear thin plastic and folding it in half transversely. Thelongitudinal edges are then heat sealed leaving a suflicient length atthe open end unsealed to provide flaps and 31.

A further important feature of this invention is the light unit 12 incombination with the sleeve 28 and together in combination withsigmoidoscope .10. Light unit 12 is releasably secured externally of thesigmoidoscope 11 while rod 23 extends internally therein. The releasablysecuring means thus requires cooperative relationship of specificallyprovided means on the sigmoidoscope 11 and on the housing 21.

Referring now to FIG. 2, the securing means associated with housing 21includes a pair of encircling arm members 32 and 33, extending from orbeing a part of housing 21, which define a central opening 34 ofsufficient size to slide over the proximal end 19 of sigmoidoscope 10.At the same time the ends of arm members 32 and 33 are spaced apart todefine an open slot 35 which is adapted to slide by and contain nipple18 on sigmoidoscopel l. In order to provide the positioning of housing21 adjacent hand guard 17, a longitudinal slot 36 is provided in thewall of the distal end 19 of sigmoidoscope 11. This slot 36 isdimensioned to slidably receive projection 25 on housing 21. Thecombination of slot 36 containing projection 25 secures and positionslighting unit 12 and prevents relative rotation between the unit 12 andsig moidoscope 11. At the same time the fitting of nipple 18 in slot 35adds stiffness to this feature and permits ready rotation of thesigmoidoscope by means of housing 21.

Where necessary or where desirable, an eye piece 13 may be fitted to theopen proximal end 19 of sigmoidoscope 11. An eye piece is generallynecessary when air is to be introduced into cylinder 14 through nipple18, or where object magnification is desired. Such an eye piece may beeconomically produced from various plastics as those mentioned andaccordingly be of a single use disposable variety.

In FIGS. 3 and 4, in one preferred form of this invention, eye piece 13includes a one piece molded plastic flared housing 37 containing anintegral lens 38. Lens 38 is not required to have a high degree ofmagnification, if indeed any magnification, and therefore need not beoptically perfect. Such plastics as Plexiglass or Lucite acrylic resinsmay be gainfully employed for eye piece 13. In addition, since only atransparent lens is basically required, no criticality attaches to thematerial or structure of housing 37. Thus, housing 37 may be of onematerial as a metal, non-metal, organic or inorganic, and the lens of adifferent transparent material sealed in place.

In order to secure eye piece 13- to sigmoidoscope 11, eye piece 13 isprovided with a pair of diametrically opposed inner projections 39 and40 which may be of plastic molded integrally with housing 37 or of ametal inserted in the plastic. Suitable I slots 41 and 42 are providedin the distal end 19 of sigmoidoscope 11 so that eye piece 13 may befitted on the end 19 of sigmoidoscope 11 with projections 39 and 40fitting into I slots 41 and 42. By moving eye piece 13 axially on distalend 19 for a short distance and then rotating eye piece 13 clockwise,eye piece 13 is secured to sigmoidoscope 10 through the interfittingrelationship of projections 39 and 40 and slots 41 and 42.

In another embodiment, the physical features are substantially the same.The principal differences in this embodiment are changes in the positionof outlet 18a, the form of housing 21a which is the air introductionmeans, and the manner of releasable attachment of cylinder 14a, lampunit 12a, and eyepiece 13a as shown in FIGS. 3 and 4.

Firstly, the arm members 32 and 33 of the first embodiment have beenmade continuous, as now shown as hollow cylindrical member 32a. Thenipple 18a is secured to member 32a and communicates with the centralopening or chamber 34 therein. A circular channel 46 is provided in theproximal face of 32a to accommodate a resilient O-ring 47. A similarchannel and O-ring (not seen) are provided in the hidden distal face ofmember 32a. In this manner, a hermetic seal can be maintained withinchamber 34a when supplied with air through pipe 18a by the sealing ofthe O-rings against abutting ends 16a and 37 Other locations for theO-ring seals are Within the scope of this invention. For example, acircular channel (not shown) may be provided in each of the abuttingends, 19 of tube 14a, and in face 37 of eye piece 13, with resilientO-rings being disposed respectively therein, to provide the desiredsealing of chamber 34.

The proximal end of cylinder 14a has been modified as shown, toaccommodate the modified structure of member 32a. A I-shaped recess 41ais seen in the viewable face of cylinder 14a, and a diametricallyopposing recess 42a is provided in the hidden face of 14a. A transverserecess 48 is provided in the outer and upper face of tube 14, near itsproximal end. Within recess 48, is perforation 49, which permitscommunication to the inside of tube 14 for the introduction of airpressure. Longitudinal slot 36 is retained to slidably key on projection25. Eye piece 13a has been modified as to its threading and theinclusion of internal projection 40a to detachably engage the slot 42aon tube 14. Another projection (not shown) engages slot 41a.

When the scope has been positioned within the body cavity, as will bedescribed, the components will then be cooperatively attached, as shownin FIG. 3, to conduct the examination. At its distal end, projection 25is provided with a J-slot 51 that detachably secures pin 52 of rod 23 infixed relation.

It will be observed that slot 48 has been carefully positioned so as tooverlap the inlet end 18i of pipe 18a. In this manner, the introductionof air through the pipe will be directed only through the matchedpassages to the inside of tube 14, as desired. Where dilation of thebody cavity is indicated, an ancillary source of air pressure (notshown), perhaps only a squeeze bulb, is detachably secured to pipe 18.Slots 41a and 42a may be tapered to provide a camming action to insuretightness of seal of eye piece.

The embodiment of this invention as illustrated in FIG. 1 is shown inits operative completeness, for example, as inserted in a body orifice.As a practical matter the practitioner may have on hand a large numberof the disposable sigmoidoscopes 10 and perhaps only one lighting unit12. At the same time the practitioner may have a large number of closedend sleeves 28 available. It is not required that the sleeve 28 bephysically included with the sigmoidoscope 11 in the same package, forexample. However, it is contemplated that one or more sleeves 28 bepacked in the same package as contains the sigmoidoscope 11.Sigmoidoscope 11 is placed in a suitable wrapper, for example, a sealedplastic bag to maintain its sterility. Sigmoidoscope 11 may besterilized previous to packaging as in one operative practice of thisinvention, or may be placed in a plastic bag and thereafter subjected toethylene oxide gas treatment for sterilization.

Upon use of this invention the sigmoidoscope 11 complete with aremovable obturator is removed from its sterile or sanitary wrapper, andaccording to standard practices inserted into the proper body opening.The practitioner then procures lighting unit 12 and places a sleeve 28over rod 23 with flaps 30 and 31 positioned to take up their position asshown in FIG. 1. Then, light unit 12 is inserted into sigmoidoscope 11and securely attached thereto as heretofore described. Finally, if to beused, eye piece 13 is also fitted to sigmoidoscope 11 as heretoforedescribed. At the completion of the examination the sigmoidoscopeassembly 10 is removed from the body cavity by parts in the reverseorder mentioned, or the assembly 10 may be removed as a unit. In eitherevent, the sigmoidoscope 11 is permanently discarded, and the sleeve 28stripped from rod unit 23 and also permanently discarded. At this pointrod 23 may be removed from projection 25 if that feature is relied uponto remove lamp 24 from the power circuit. In one preferred embodiment ofthis invention a recharging unit is provided (not shown) so that housing21 fits therein for recharging and storage purposes. Such rechargingunits are well known in the art.

Releasably secured or releasably attached denotes ordinary and usualdetaching means, for example, after each use rather than an assemblyconnection as a structural feature. Single use disposable indicatespermanent discarding after a sole use.

The speculum of this invention may be suitably optically darkened toprevent unwanted or undesirable light reflection. In this respect,linear polyolefins are ordinarily opaque with minimal light reflection.One preferred procedure is to reduce the light reflection along theinner surface of tubes 14 and 14a by abrading the surface with a wirebrush means or the like. It is also possible to reduce glare by tintingthe transparent lens 53 of eye piece 13.

While other modifications of this invention and variations of apparatusmay be employed within the scope of this invention and have not beendescribed or illustrated, the invention is intended to include all suchmodifications as may ordinarily be embraced within the following claims.

What is claimed is:

1. A lighting unit for use with a speculum device including acylindrical barrel for insertion into a proper body cavity, saidlighting unit comprising,

(a) a housing assembly adapted to contain a portable source ofelectrical power,

(b) means on said assembly to at least partly encircle the exterior ofsaid barrel for releasable attachment thereto,

() support means releasably attached at one end thereof to said housingassembly and extending into said barrel to lie adjacent the walltherein,

(d) lamp means secured to the free end of said support means forproviding illumination within said speculum, and

(e) conducting means connecting said lamp means to said source of power,and

(f) separate disposable contamination prevention cover surrounding bothsaid support and lamp means to prevent contamination thereof, said covercomprising an at least partially translucent end thereabout adapted totransmit light through one end thereof and being suitable for a singleuse and discarding thereafter.

2. The invention according to claim 1 wherein the sleeve includes atleast one flap extension at the open end thereof of suflicient length soas to be manually graspable while said light unit is being positionedwithin said barrel.

3. A light unit for use with a speculum device consisting of a hollowbarrel for insertion into a body cavity, a guard secured about saidbarrel spaced from its proximal end to limit said insertion defining anelongated distal end from said guard, and an eye piece adapted to bedetachably secured to said proximal end by means of lugs provided on theinternal periphery of said eye piece, said light unit comprising,

(a) a housing assembly adapted to contain a portable electrical powersource and to lie adjacent the proximal end of said barrel,

(b) arm means on said housing at least partly encircling said proximalend for releasable attachment to said barrel,

(c) fluid conduit means secured to the outer surface of said arm meanscommunicating between the environment and the inner surface of said armmeans,

(d) an axial projection disposed internally of said arm means andadapted to slidably engage an axial slot in the proximal end of saidbarrel,

(e) hollow rod means detachably secured at one end thereof to said axialprojection so as to lie axially within said barrel adjacent the wallthereof,

(f) lamp means capable of providing illumination within said barrelsecured to the free end of said rod means, and

(g) conducting means disposed within said rod means connecting said lampmeans with said source of power for energization thereof.

4. A light unit for use with a speculum device consisting of:

a hollow barrel for insertion into a body cavity, a guard secured aboutsaid barrel and spaced from its proximal end to limit the degree ofinsertion thereof, an eye piece adapted to be detachably secured to saidproximal end by means of lugs provided on the internal periphery of saideye piece, said light unit comprising:

(a) a housing assembly adapted to contain a portable electric powersource to be attached about the proximal end of said barrel,

(b) hollow cylindrical means on said assembly encircling at least aportion of the exterior of said proximal end, and adapted for releasableattachment thereto,

(c) fluid conduit means secured to the outer surface of said hollowcylindrical means communicating between the environment and an annularchamber defined by the inner surface of said cylindrical means and theouter surface of said barrel,

(d) an axial projection disposed internally of said hollow cylindricalmeans and adapted to slidably engage an axial slot, provided in theproximal end of said barrel,

(e) means disposed between the abutting portions of said barrel, hollowmeans and eye piece, when assembled, to hermetically seal annularchamber,

(f) hollow rod means detachably secured at one end thereof to said axialprojection so as to lie axially within said barrel adjacent the wallthereof,

(g) lamp means capable of providing illumination within said barrelsecured to the free end of said rod means, and

(h) conducting means disposed within said rod means connecting lampmeans with said source of power for energization thereof.

5. The invention as recited in claim 4 wherein a separate disposablecontamination prevention means surrounds both said rod and illuminationmeans to prevent contamination thereof, said contamination preventionmeans being suitable for a single use and discarding thereafter.

References Cited UNITED STATES PATENTS 939,034 11/1909 Kolb l28--61,662,227 3/ 1928 Allyn 1287 1,704,397 3/1929 Meitzler 1286 3,032,0315/1962 Moore 128--6 3,03 8,466 6/ 1962 Moore 1284 FOREIGN PATENTS1,251,506 12/ 1960 France.

547,291 3/1932 Germany.

RICHARD A. GAUDET, Primary Examiner.

K. L. HOWELL, Assistant Examiner.

